NOTE that the software section 5c may be of at least some heuristic relevance to other types of devices in some ways.
The FDA issued a gudance entitled Class II Special Controls Guideline: Nucleic Acid-Based In Vitro Diagnostic Devices for the Detection of Mycobacterium tuberculosis Complex and Genetic Mutations Associated with Mycobacterium tuberculosis Complex Antibiotic Resistance in Respiratory Specimens” dated 22-Oct-2014.
Section 5c of this guidance addresses software. In addition to referring to the general software guidance it specifically requests a clear description of how raw signals are converted into a result. It also has a lengthy discussion of level of concern. Although in section 4 it states the device can provide false negative results for tuberculosis allowing for disease progression and transmission to others. In Secton 5c it stress Level of concern must be determined without considering mitigation and then says software would normally be considered moderate for this type of device but you must determine the actual level of concern from your hazard analysis.
Section 5c also states that “If any significant changes are made to the hardware or software after the completion of the clinical studies but before the clearance and distribution of the device, you must perform a risk assessment and include it in your 510(k) submission.”
Section 5c then provides a list of references that may be helpful but note that the reference to AAMI SW68 is probably obsolete and was unitentional as the current medical device software lifecyle standard is EN/AAMI/IEC 62304.